Something to think about: We must always remember that building each other up actually consists of two separate and complementary aspects: the actual lifting or building up and the avoidance of pulling or tearing down. The principle is clearly seen in comparing Paul's instruction in I Thessalonians (above) with what he says in the Book of Ephesians:
"Do not let any unwholesome talk come out of your mouths, but only what is helpful for building others up according to their needs, that it may benefit those who listen" (Ephesians 4:29).
The two instructions are identical in telling us to build each other up, but while Thessalonians stresses encouraging each other to do so, Ephesians stresses not discouraging each other. It is usually easier to see when we are doing the first rather than the second of these things, but we should certainly do both. How much time do we spend thinking about how we can build each other up – in encouragement and also in not discouraging?